After a close first half that ended with Phoenix leading 44-40, the Suns jumped out to an early third-quarter lead, taking a double-digit advantage midway through and finishing with a 15-point lead as they outscored the Celtics 21-10 in the period.

Boston had fewer positives. Jordan Mickey scored 18 points and R.J. Hunter had 17. Hunter went 4-for-6 from 3-point range, continuing his stretch of summer sharpshooting. He is 9 of 16 from long distance in summer league play.

Both teams return to action Tuesday, with the Celtics playing the Dallas Mavericks and the Suns facing the Miami Heat.